It may help to to think, as a rule, that if a candlestick body is hollow it is 'light' in weight and therefore rising upward (The Close > The Open).Conversely, if it is 'filled' it is 'heavy' in weight and therefore falling downward (The Close < The Open).

The colour of the bar (green or red) reflects the relationship to the previous bar's close.If The Close on the current bar being looked at is greater than the previous bar close, the candle will be green regardless of the relationship between the current bar Open and Close (The Close > The Previous Close)If The Close on the current bar being looked at is less than the previous bar close, the candle will be red regardless of the relationship between the current bar Open and Close (The Close < The Previous Close)

This explains why you can have a hollow or filled Candle of either colour.